1. Field of the Disclosure
The disclosure relates to a printing apparatus. More particularly, the disclosure relates to a three-dimensional printing apparatus.
2. Description of Related Art
There are many different technologies currently used to build physical three-dimensional (3-D) models using additive manufacturing technology, for example, building a model layer by layer. Typically, a virtual design of the 3-D model using additive manufacturing technology, for example, represented through computer-aided design (CAD) software or the like, is transformed into a plurality of thin (quasi-two-dimensional) cross-sectional layers which are built on one another in succession. At the same time, various technologies which can form a plurality of thin cross-sectional layers are carried out progressively. For instance, the thin cross-sectional layers may be formed, wherein a printing module of a printing apparatus usually can be moved along the X-Y plane above a base in the XYZ coordinate system which is constructed according to the virtual design data of the three-dimensional model, so as to extrude or deposit material in correct shape of the cross-sectional layer. The deposited material may then harden naturally or be cured by, for example, powerful light source, to form the desired cross-sectional layer. Therefore, by the printing module gradually moves along the Z axis layer by layer, a plurality of cross-sectional layers are stacked gradually along the Z axis, and a 3-D object is formed under the condition of the deposited material further being cured gradually and layer by layer.
Taking the technology of forming a 3-D object by curing the deposited material through light source as an example, a moving stage of the printing apparatus is adapted to be submerged in the liquid forming material which is filled in the tank, and the light source module illuminates the liquid forming material on the X-Y plane, so that the liquid forming material is cured and stacked on the moving stage. As such, by moving the moving stage of the printing apparatus along the Z axis gradually and layer by layer, the liquid forming material may be gradually cured layer by layer and stacked to form the 3-D object. During the forming process of the 3-D object, the printing apparatus usually shields the tank with an outer cover so that the liquid forming material can be cured by the illuminating of the light source of the printing apparatus. However, when a user opens the outer cover and picks up the 3-D object after the 3-D object is completed, the rest of the liquid forming material which has not been cured may be illuminated by the external light source and induce undesired or unexpected solidification. Furthermore, the user may happen to accidently touch the liquid forming material when he/she picks up the 3-D object, or the liquid forming material may spill if the 3-D object accidently falls. Thus, if the liquid forming material is exposed, the operating function of the printing apparatus may be affected.